1. FIELD OF THE INVENTION
This invention relates to a new and unique method or technique for the fabrication of reinforced composites. Reinforced composites are used in a wide variety of applications; for example, carbon composites are useful in the construction of structures having to withstand high-temperature environments, and are, therefore, useful in constructing nose tips, rocket nozzles, heat shields, gas turbines in atomic reactors and bioprosthetic devices requiring thermomechanical properties. The improved reinforced composites demonstrate superior thermo-mechanical and thermo-chemical properties with improved material quality and reduced fabrication costs.
2. BRIEF DESCRIPTION OF THE PRIOR ART
A wide range of reinforced composite structures and materials are now available. The AIAA Paper No. 76-607 presented at the Propulsion Conference in Palo Alto, Calif. on July 26-29, 1976, entitled "Development of a 4D Reinforced Carbon-Carbon Composite," by M. A. Maister, Societe Europeene de Propulsion, Blanquefort, France, discusses significant properties of a carbon composite. Some conventional carbon composite structures are fabricated from prerigidized rods, which are produced by a pultrusion process, and assembled in a geometric pattern or geometric structure. Others are woven using carbon yarn. A variety of geometric structures have been developed to provide specific characteristics which satisfy physical requirements that are imposed by the ultimate application of the carbon composite.
The filler or matrix is formed in a carbon composite through either the liquid or dry process. The dry process consists of continually depositing carbon, inside the porosity or voids within the structure, by cracking therein a gaseous hydrocarbon such as methane. The liquid process consists of impregnating the porous texture of the structure with an organic compound or precursor which is converted into a char by carbonization. The organic compound consists of a thermo-setting resin such as phenolic or furane resin or a fusible substance such as pitch. Due to the low volume of yield of char in these products, the impregnation carbonization cycle is generally repeated several times.